Apparatus for the measurement of the characteristics of rubber tires, in particular motor vehicle tires

Abstract

An apparatus for measuring the properties of rubber elastic tires, in particular motor vehicle tires, in dependence on simulated driving loads and/or running states for the rotation of a tire to be measured at a tire contact patch and apparatus for simulating driving loads and/or running states, in particular with respect to the rotational speed, to the weight load and to the slip angle of the tire, wherein a device for measuring the visco-elastic properties of the tire is provided at the apparatus and is designed for direct use on the tire disposed in the apparatus.

1. An apparatus for measuring the properties of rubber elastic tires, in particular motor vehicle tires, in dependence on simulated driving loads and/or running states with means ( 1 ) for rotating a tire ( 8 ) to be measured at a tire contact patch and means ( 5 ) for simulating driving loads and/or running states, in particular with respect to the rotational speed, to the weight load and to the slip angle of the tire ( 8 ), characterized in that a device ( 9 ) for measuring the visco-elastic properties of the tire ( 8 ) is provided at the apparatus and is designed for direct use on the tire ( 8 ) disposed in the apparatus and further characterized in that the device ( 9 ) includes a measuring body ( 12 ) which has a measuring head ( 13 ), which can be placed onto a tire ( 8 ) and which is displaceably mounted relative to a holder ( 11 ) fastened to the apparatus, means ( 16 ) for moving the measuring body ( 12 ) to and fro and means ( 17 ,  24 ) for measuring the displacement path of the measuring head ( 13 ) and/or the force acting on the measuring head ( 13 ) during the moving to and fro of the measuring body ( 12 ). 
   
   
     2. An apparatus in accordance with  claim 1 , characterized in that a zero position of the measuring head ( 13 ) is fixed by a pre-determined penetration depth. 
   
   
     3. An apparatus in accordance with  claim 2 , characterized in that the penetration depth in the zero position is selected such that the deflection of an indenter of the measuring head ( 13 ) lies in a region of an at least approximately linear force/path ratio. 
   
   
     4. An apparatus in accordance with  claim 3 , characterized in that the penetration depth in the zero position amounts to approximately 100 to approximately 500 μm. 
   
   
     5. An apparatus in accordance with  claim 1 , characterized in that the measuring head ( 13 ) projects beyond the housing ( 11 ) in accordance with the penetration depth. 
   
   
     6. An apparatus in accordance with  claim 1 , characterized in that means are provided by which the measuring head ( 13 ) can be moved out of the housing ( 11 ) into a zero position of the measuring head. 
   
   
     7. An apparatus in accordance with  claim 1 , characterized in that a zero position of the measuring head ( 13 ) can be selected. 
   
   
     8. An apparatus in accordance with  claim 1 , characterized in that the deflection of an indenter of the measuring head ( 13 ) during the measurement is fixed via the deflection path. 
   
   
     9. An apparatus in accordance with  claim 8 , characterized in that the deflection path can be selected. 
   
   
     10. An apparatus in accordance with  claim 1 , characterized in that a deflection of an indenter ( 13 ) is selected to be so small that the tire ( 8 ) behaves in an approximately linear manner. 
   
   
     11. An apparatus in accordance with  claim 10 , characterized in that the deflection amounts to approximately 5 μm to approximately 25 μm. 
   
   
     12. An apparatus in accordance with  claim 1 , characterized in that the frequency of the to and fro movement of the measuring head ( 13 ) can be selected. 
   
   
     13. An apparatus in accordance with  claim 1 , characterized in that the frequency of the to and fro movement of the measuring head ( 13 ) amounts to approximately 1 Hertz to approximately 15 Hertz. 
   
   
     14. An apparatus in accordance with  claim 1 , characterized in that means ( 25 ) are provided for determining the temperature of the tire ( 8 ). 
   
   
     15. An apparatus in accordance with  claim 1 , characterized in that a piezo-element ( 16 ), in particular a so-called stack translator, is provided to move the measuring head ( 13 ). 
   
   
     16. An apparatus in accordance with  claim 15 , characterized in that the piezo-element ( 16 ) is arranged in a feedback loop with a path-measuring device ( 24 ). 
   
   
     17. An apparatus in accordance with  claim 1 , characterized in that the measuring head ( 13 ) has a tip ( 18 ) formed as an indenter in accordance with DIN 53505. 
   
   
     18. An apparatus for measuring the properties of rubber elastic tires. in particular motor vehicle tires, in dependence on simulated driving loads and/or running states with means ( 1 ) for rotating a tire ( 8 ) to be measured at a tire contact patch and means ( 5 ) for simulating driving loads and/or running states, in particular with respect to the rotational speed, to the weight load and to the slip angle of the tire ( 8 ), characterized in that a device ( 9 ) for measuring the visco-elastic properties of the tire ( 8 ) is provided at the apparatus and is designed for direct use on the tire ( 8 ) disposed in the apparatus further characterized in that the apparatus has a rotatable disk ( 1 ) on which a tire ( 8 ) to be measured can be rolled off and there is arranged above the disk ( 1 ) an axle shaft ( 4 ) on which a tire ( 8 ) to be measured can be put in place and which is rotatably mounted in a holding apparatus ( 5 ) by means of which the tire ( 8 ) can be pressed onto the disk ( 1 ) via the axle shaft ( 4 ) and can be changed in its orientation relative to the disk ( 1 ). 
   
   
     19. An apparatus for measuring the properties of rubber elastic tires, in particular motor vehicle tires, in dependence on simulated driving loads and/or running states with means ( 1 ) for rotating a tire ( 8 ) to be measured at a tire contact patch and means ( 5 ) for simulating driving loads and/or running states, in particular with respect to the rotational speed, to the weight load and to the slip angle of the tire ( 8 ), characterized in that a device ( 9 ) for measuring the visco-elastic properties of the tire ( 8 ) is provided at the apparatus and is designed for direct use on the tire ( 8 ) disposed in the apparatus and further characterized in that means are provided by which a comparison of tires ( 8 ) heated by loading with tires heated in a thermal conditioning device can be carried out. 
   
   
     20. An apparatus for measuring the properties of rubber elastic tires, in particular motor vehicle tires, in dependence on simulated driving loads and/or running states with means ( 1 ) for rotating a tire ( 8 ) to be measured at a tire contact patch and means ( 5 ) for simulating driving loads and/or running states, in particular with respect to the rotational speed, to the weight load and to the slip angle of the tire ( 8 ), characterized in that a device ( 9 ) for measuring the visco-elastic properties of the tire ( 8 ) is provided at the apparatus and is designed for direct use on the tire ( 8 ) disposed in the apparatus and further characterized in that means are provided by which a comparison with the slip energy which occurs in each case can be carried out.